slack: retry 429 errors

Fix #2111

Signed-off-by: Julien Pivotto <[email protected]>

notify/slack/slack.go

@@ -49,7 +49,7 @@ func New(c *config.SlackConfig, t *template.Template, l log.Logger) (*Notifier,
 		tmpl:    t,
 		logger:  l,
 		client:  client,
-		retrier: &notify.Retrier{},
+		retrier: &notify.Retrier{RetryCodes: []int{http.StatusTooManyRequests}},
 	}, nil
 }
 

notify/slack/slack_test.go

@@ -15,6 +15,7 @@ package slack
 
 import (
 	"fmt"
+	"net/http"
 	"testing"
 
 	"github.com/go-kit/kit/log"
@@ -35,7 +36,8 @@ func TestSlackRetry(t *testing.T) {
 	)
 	require.NoError(t, err)
 
-	for statusCode, expected := range test.RetryTests(test.DefaultRetryCodes()) {
+	retryCodes := append(test.DefaultRetryCodes(), http.StatusTooManyRequests)
+	for statusCode, expected := range test.RetryTests(retryCodes) {
 		actual, _ := notifier.retrier.Check(statusCode, nil)
 		require.Equal(t, expected, actual, fmt.Sprintf("error on status %d", statusCode))
 	}